/*
 * Copyright (c) 2024 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

function source(): number | null {
    return null
}

function pass(data: number | null): number | null {
    return data
}

function validate(data: number | null): number {
    if (data == null) return 0
    return data
}

function sink(data: number | null) {
    if (data == null) throw new Error("Error!")
}

function bad() {
    let data = source()
    data = pass(data)
    sink(data)
}

function good() {
    let data = source()
    data = validate(data)
    sink(data)
}
